Comprehensive Analysis of Genes Associated With Sudden Infant Death Syndrome

CLINICAL CASES OF LIFE-THREATENING ARRHYTHMIAS: LONG AND SHORT QT SYNDROMES

OBJECTIVE

The aim: To present clinical cases of sudden cardiac death in patients with prolonged and shortened QT interval.

PATIENTS AND METHODS

Materials and methods: The study includes description of two different clinical cases with prolonged and shortened QT interval after sudden cardiac death. Verification of the diagnosis was performed using the criteria recommended by the European Society of Cardiology (ESC) and European Heart Rhythm Association (EHRA).

RESULTS

Clinical case: Two clinical cases of syncopе with life-threatening arrhythmias, confirmed by electrocardiographic and clinical diagnostic criteria, indicating a change in the dispersion of the QT interval, are presented. The first case represents a patient with intermittent syncope. The patient had previously had attacks of sudden palpitations with fainting. The patient came after another episode of syncope. Further follow-up revealed clinical and electrocardiographic signs of ventricular tachycardia paroxysm. Than the prolongation of the QT interval is set. In this clinical case, verification of QT prolongation syndrome was established in the elderly. Another clinical case is associated with QT syndrome, which remains difficult to diagnose. Such cases have been described relatively recently. The clinical picture of the syndrome of short QT interval in the presented clinical case was characterized by the appearance of syncopal states. The patient showed changes in the adjusted QT interval <320 ms. The causes of syncope in a patient with a short QT interval were paroxysms of atrial fibrillation (AF) or ventricular arrhythmias. At the same time the anatomical structure of a myocardium remains normal and unchanged. The hereditary nature of the disease in the patient has been proven.

CONCLUSION

Conclusions: Timely diagnosis of prolongation (LQTS) or shortening (SQTS) of the QT interval after ECG and Holter monitoring allows you to identify a group of patients with an increased risk of developing ventricular arrhythmias, syncope and sudden cardiac death. Implantation of a cardioverter-defibrillator is an effective and safe method of preventing sudden cardiac death in patients with long and short QT syndromes.

Epidemiology of sudden infant death syndrome in Mexico, 2005-2020

BACKGROUND

Sudden Infant Death Syndrome (SIDS) constitutes one of the main causes of mortality in children under one year of age in developed countries; it's frequency to varies geographically. In Mexico the real incidence of SIDS is not known.

METHODS

National databases of deaths in children under one year of age, from 2005 to 2020, were analyzed, due to Sudden Unexpected Infant Death (SUID) [SIDS (R95), accidental suffocation in a sleeping environment (W75), and other ill-defined and unspecified causes of mortality (R99), according to the International Classification of Diseases, tenth revision (ICD 10)]. Mortality rates per year of occurrence due to SUID and their subcategories were calculated. Simple frequencies of SIDS were obtained per year and month of occurrence, state of residence, age, place of death, and access to social security services.

RESULTS

In the study period 473,545 infant deaths occurred; 7,714 (1.62%) deaths were due to SUID; of these, 6,489 (84%) were due to SIDS, which is among the 10 leading causes of infant death in Mexico. The average mortality rate for SUID was 22.4/100,000 live births, for SIDS was 18.8/100,000 live births. Mortality rates within the states were variable, ranging from 2.4/100,000 to 105.1/100,000 live births. In 81% of SIDS records there was no autopsy; 38% of deaths due to SIDS occurred in infants under one month of age, up to 87% of deaths occurred in families without social security services or it was unknown, and 76.2% of deaths occurred at home. Deaths were more frequent during the last months of autumn and during winter.

CONCLUSION

In Mexico there is an underregistry of SIDS as cause of death, along with other SUID categories. Health workers need to be trained to improve diagnosis and data registration, including the practice of autopsies; additionally, it is necessary to implement a public health campaign.